The social conditioning makes a normal man who feels attraction toward women, not to feel sexual attraction towards the women in his close relationship like mother and sister and sister in law.
Similarly, it is the social conditioning for reason known or unknown due to which a man feels no attraction towards women, but to men. One needs to address one’s feelings to correct them with the help of medicines and psychological and psychiatric help.
If one still finds it not working, then one has to refrain from establishing sexual relationship with men or a woman as his wife. We have examples of people who choose celibacy. The medical assistance is there to help live a life of celibacy.